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bdd1545b | 1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * | |
4 | * Copyright (C) 1997-2003 Erez Zadok | |
5 | * Copyright (C) 2001-2003 Stony Brook University | |
6 | * Copyright (C) 2004-2007 International Business Machines Corp. | |
7 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> | |
8 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
9 | * Tyler Hicks <tyhicks@ou.edu> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License as | |
13 | * published by the Free Software Foundation; either version 2 of the | |
14 | * License, or (at your option) any later version. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, but | |
17 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | * General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU General Public License | |
22 | * along with this program; if not, write to the Free Software | |
23 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
24 | * 02111-1307, USA. | |
25 | */ | |
26 | ||
27 | #include <linux/dcache.h> | |
28 | #include <linux/file.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/namei.h> | |
31 | #include <linux/skbuff.h> | |
32 | #include <linux/crypto.h> | |
33 | #include <linux/mount.h> | |
34 | #include <linux/pagemap.h> | |
35 | #include <linux/key.h> | |
36 | #include <linux/parser.h> | |
37 | #include <linux/fs_stack.h> | |
38 | #include <linux/slab.h> | |
39 | #include <linux/magic.h> | |
40 | #include "ecryptfs_kernel.h" | |
41 | ||
42 | /** | |
43 | * Module parameter that defines the ecryptfs_verbosity level. | |
44 | */ | |
45 | int ecryptfs_verbosity = 0; | |
46 | ||
47 | module_param(ecryptfs_verbosity, int, 0); | |
48 | MODULE_PARM_DESC(ecryptfs_verbosity, | |
49 | "Initial verbosity level (0 or 1; defaults to " | |
50 | "0, which is Quiet)"); | |
51 | ||
52 | /** | |
53 | * Module parameter that defines the number of message buffer elements | |
54 | */ | |
55 | unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; | |
56 | ||
57 | module_param(ecryptfs_message_buf_len, uint, 0); | |
58 | MODULE_PARM_DESC(ecryptfs_message_buf_len, | |
59 | "Number of message buffer elements"); | |
60 | ||
61 | /** | |
62 | * Module parameter that defines the maximum guaranteed amount of time to wait | |
63 | * for a response from ecryptfsd. The actual sleep time will be, more than | |
64 | * likely, a small amount greater than this specified value, but only less if | |
65 | * the message successfully arrives. | |
66 | */ | |
67 | signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; | |
68 | ||
69 | module_param(ecryptfs_message_wait_timeout, long, 0); | |
70 | MODULE_PARM_DESC(ecryptfs_message_wait_timeout, | |
71 | "Maximum number of seconds that an operation will " | |
72 | "sleep while waiting for a message response from " | |
73 | "userspace"); | |
74 | ||
75 | /** | |
76 | * Module parameter that is an estimate of the maximum number of users | |
77 | * that will be concurrently using eCryptfs. Set this to the right | |
78 | * value to balance performance and memory use. | |
79 | */ | |
80 | unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; | |
81 | ||
82 | module_param(ecryptfs_number_of_users, uint, 0); | |
83 | MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " | |
84 | "concurrent users of eCryptfs"); | |
85 | ||
86 | void __ecryptfs_printk(const char *fmt, ...) | |
87 | { | |
88 | va_list args; | |
89 | va_start(args, fmt); | |
90 | if (fmt[1] == '7') { /* KERN_DEBUG */ | |
91 | if (ecryptfs_verbosity >= 1) | |
92 | vprintk(fmt, args); | |
93 | } else | |
94 | vprintk(fmt, args); | |
95 | va_end(args); | |
96 | } | |
97 | ||
98 | /** | |
99 | * ecryptfs_init_lower_file | |
100 | * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with | |
101 | * the lower dentry and the lower mount set | |
102 | * | |
103 | * eCryptfs only ever keeps a single open file for every lower | |
104 | * inode. All I/O operations to the lower inode occur through that | |
105 | * file. When the first eCryptfs dentry that interposes with the first | |
106 | * lower dentry for that inode is created, this function creates the | |
107 | * lower file struct and associates it with the eCryptfs | |
108 | * inode. When all eCryptfs files associated with the inode are released, the | |
109 | * file is closed. | |
110 | * | |
111 | * The lower file will be opened with read/write permissions, if | |
112 | * possible. Otherwise, it is opened read-only. | |
113 | * | |
114 | * This function does nothing if a lower file is already | |
115 | * associated with the eCryptfs inode. | |
116 | * | |
117 | * Returns zero on success; non-zero otherwise | |
118 | */ | |
119 | static int ecryptfs_init_lower_file(struct dentry *dentry, | |
120 | struct file **lower_file) | |
121 | { | |
122 | const struct cred *cred = current_cred(); | |
123 | struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); | |
124 | struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); | |
125 | int rc; | |
126 | ||
127 | rc = ecryptfs_privileged_open(lower_file, lower_dentry, lower_mnt, | |
128 | cred); | |
129 | if (rc) { | |
130 | printk(KERN_ERR "Error opening lower file " | |
131 | "for lower_dentry [0x%p] and lower_mnt [0x%p]; " | |
132 | "rc = [%d]\n", lower_dentry, lower_mnt, rc); | |
133 | (*lower_file) = NULL; | |
134 | } | |
135 | return rc; | |
136 | } | |
137 | ||
138 | int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) | |
139 | { | |
140 | struct ecryptfs_inode_info *inode_info; | |
141 | int count, rc = 0; | |
142 | ||
143 | inode_info = ecryptfs_inode_to_private(inode); | |
144 | mutex_lock(&inode_info->lower_file_mutex); | |
145 | count = atomic_inc_return(&inode_info->lower_file_count); | |
146 | if (WARN_ON_ONCE(count < 1)) | |
147 | rc = -EINVAL; | |
148 | else if (count == 1) { | |
149 | rc = ecryptfs_init_lower_file(dentry, | |
150 | &inode_info->lower_file); | |
151 | if (rc) | |
152 | atomic_set(&inode_info->lower_file_count, 0); | |
153 | } | |
154 | mutex_unlock(&inode_info->lower_file_mutex); | |
155 | return rc; | |
156 | } | |
157 | ||
158 | void ecryptfs_put_lower_file(struct inode *inode) | |
159 | { | |
160 | struct ecryptfs_inode_info *inode_info; | |
161 | ||
162 | inode_info = ecryptfs_inode_to_private(inode); | |
163 | if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, | |
164 | &inode_info->lower_file_mutex)) { | |
165 | filemap_write_and_wait(inode->i_mapping); | |
166 | fput(inode_info->lower_file); | |
167 | inode_info->lower_file = NULL; | |
168 | mutex_unlock(&inode_info->lower_file_mutex); | |
169 | } | |
170 | } | |
171 | ||
172 | enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, | |
173 | ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, | |
174 | ecryptfs_opt_ecryptfs_key_bytes, | |
175 | ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, | |
176 | ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, | |
177 | ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, | |
178 | ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, | |
179 | ecryptfs_opt_check_dev_ruid, | |
180 | ecryptfs_opt_err }; | |
181 | ||
182 | static const match_table_t tokens = { | |
183 | {ecryptfs_opt_sig, "sig=%s"}, | |
184 | {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, | |
185 | {ecryptfs_opt_cipher, "cipher=%s"}, | |
186 | {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, | |
187 | {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, | |
188 | {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, | |
189 | {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, | |
190 | {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, | |
191 | {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, | |
192 | {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, | |
193 | {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, | |
194 | {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, | |
195 | {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, | |
196 | {ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"}, | |
197 | {ecryptfs_opt_err, NULL} | |
198 | }; | |
199 | ||
200 | static int ecryptfs_init_global_auth_toks( | |
201 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
202 | { | |
203 | struct ecryptfs_global_auth_tok *global_auth_tok; | |
204 | struct ecryptfs_auth_tok *auth_tok; | |
205 | int rc = 0; | |
206 | ||
207 | list_for_each_entry(global_auth_tok, | |
208 | &mount_crypt_stat->global_auth_tok_list, | |
209 | mount_crypt_stat_list) { | |
210 | rc = ecryptfs_keyring_auth_tok_for_sig( | |
211 | &global_auth_tok->global_auth_tok_key, &auth_tok, | |
212 | global_auth_tok->sig); | |
213 | if (rc) { | |
214 | printk(KERN_ERR "Could not find valid key in user " | |
215 | "session keyring for sig specified in mount " | |
216 | "option: [%s]\n", global_auth_tok->sig); | |
217 | global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; | |
218 | goto out; | |
219 | } else { | |
220 | global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; | |
221 | up_write(&(global_auth_tok->global_auth_tok_key)->sem); | |
222 | } | |
223 | } | |
224 | out: | |
225 | return rc; | |
226 | } | |
227 | ||
228 | static void ecryptfs_init_mount_crypt_stat( | |
229 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
230 | { | |
231 | memset((void *)mount_crypt_stat, 0, | |
232 | sizeof(struct ecryptfs_mount_crypt_stat)); | |
233 | INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); | |
234 | mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); | |
235 | mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; | |
236 | } | |
237 | ||
238 | /** | |
239 | * ecryptfs_parse_options | |
240 | * @sb: The ecryptfs super block | |
241 | * @options: The options passed to the kernel | |
242 | * @check_ruid: set to 1 if device uid should be checked against the ruid | |
243 | * | |
244 | * Parse mount options: | |
245 | * debug=N - ecryptfs_verbosity level for debug output | |
246 | * sig=XXX - description(signature) of the key to use | |
247 | * | |
248 | * Returns the dentry object of the lower-level (lower/interposed) | |
249 | * directory; We want to mount our stackable file system on top of | |
250 | * that lower directory. | |
251 | * | |
252 | * The signature of the key to use must be the description of a key | |
253 | * already in the keyring. Mounting will fail if the key can not be | |
254 | * found. | |
255 | * | |
256 | * Returns zero on success; non-zero on error | |
257 | */ | |
258 | static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, | |
259 | uid_t *check_ruid) | |
260 | { | |
261 | char *p; | |
262 | int rc = 0; | |
263 | int sig_set = 0; | |
264 | int cipher_name_set = 0; | |
265 | int fn_cipher_name_set = 0; | |
266 | int cipher_key_bytes; | |
267 | int cipher_key_bytes_set = 0; | |
268 | int fn_cipher_key_bytes; | |
269 | int fn_cipher_key_bytes_set = 0; | |
270 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
271 | &sbi->mount_crypt_stat; | |
272 | substring_t args[MAX_OPT_ARGS]; | |
273 | int token; | |
274 | char *sig_src; | |
275 | char *cipher_name_dst; | |
276 | char *cipher_name_src; | |
277 | char *fn_cipher_name_dst; | |
278 | char *fn_cipher_name_src; | |
279 | char *fnek_dst; | |
280 | char *fnek_src; | |
281 | char *cipher_key_bytes_src; | |
282 | char *fn_cipher_key_bytes_src; | |
283 | u8 cipher_code; | |
284 | ||
285 | *check_ruid = 0; | |
286 | ||
287 | if (!options) { | |
288 | rc = -EINVAL; | |
289 | goto out; | |
290 | } | |
291 | ecryptfs_init_mount_crypt_stat(mount_crypt_stat); | |
292 | while ((p = strsep(&options, ",")) != NULL) { | |
293 | if (!*p) | |
294 | continue; | |
295 | token = match_token(p, tokens, args); | |
296 | switch (token) { | |
297 | case ecryptfs_opt_sig: | |
298 | case ecryptfs_opt_ecryptfs_sig: | |
299 | sig_src = args[0].from; | |
300 | rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, | |
301 | sig_src, 0); | |
302 | if (rc) { | |
303 | printk(KERN_ERR "Error attempting to register " | |
304 | "global sig; rc = [%d]\n", rc); | |
305 | goto out; | |
306 | } | |
307 | sig_set = 1; | |
308 | break; | |
309 | case ecryptfs_opt_cipher: | |
310 | case ecryptfs_opt_ecryptfs_cipher: | |
311 | cipher_name_src = args[0].from; | |
312 | cipher_name_dst = | |
313 | mount_crypt_stat-> | |
314 | global_default_cipher_name; | |
315 | strncpy(cipher_name_dst, cipher_name_src, | |
316 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
317 | cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; | |
318 | cipher_name_set = 1; | |
319 | break; | |
320 | case ecryptfs_opt_ecryptfs_key_bytes: | |
321 | cipher_key_bytes_src = args[0].from; | |
322 | cipher_key_bytes = | |
323 | (int)simple_strtol(cipher_key_bytes_src, | |
324 | &cipher_key_bytes_src, 0); | |
325 | mount_crypt_stat->global_default_cipher_key_size = | |
326 | cipher_key_bytes; | |
327 | cipher_key_bytes_set = 1; | |
328 | break; | |
329 | case ecryptfs_opt_passthrough: | |
330 | mount_crypt_stat->flags |= | |
331 | ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; | |
332 | break; | |
333 | case ecryptfs_opt_xattr_metadata: | |
334 | mount_crypt_stat->flags |= | |
335 | ECRYPTFS_XATTR_METADATA_ENABLED; | |
336 | break; | |
337 | case ecryptfs_opt_encrypted_view: | |
338 | mount_crypt_stat->flags |= | |
339 | ECRYPTFS_XATTR_METADATA_ENABLED; | |
340 | mount_crypt_stat->flags |= | |
341 | ECRYPTFS_ENCRYPTED_VIEW_ENABLED; | |
342 | break; | |
343 | case ecryptfs_opt_fnek_sig: | |
344 | fnek_src = args[0].from; | |
345 | fnek_dst = | |
346 | mount_crypt_stat->global_default_fnek_sig; | |
347 | strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); | |
348 | mount_crypt_stat->global_default_fnek_sig[ | |
349 | ECRYPTFS_SIG_SIZE_HEX] = '\0'; | |
350 | rc = ecryptfs_add_global_auth_tok( | |
351 | mount_crypt_stat, | |
352 | mount_crypt_stat->global_default_fnek_sig, | |
353 | ECRYPTFS_AUTH_TOK_FNEK); | |
354 | if (rc) { | |
355 | printk(KERN_ERR "Error attempting to register " | |
356 | "global fnek sig [%s]; rc = [%d]\n", | |
357 | mount_crypt_stat->global_default_fnek_sig, | |
358 | rc); | |
359 | goto out; | |
360 | } | |
361 | mount_crypt_stat->flags |= | |
362 | (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES | |
363 | | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); | |
364 | break; | |
365 | case ecryptfs_opt_fn_cipher: | |
366 | fn_cipher_name_src = args[0].from; | |
367 | fn_cipher_name_dst = | |
368 | mount_crypt_stat->global_default_fn_cipher_name; | |
369 | strncpy(fn_cipher_name_dst, fn_cipher_name_src, | |
370 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
371 | mount_crypt_stat->global_default_fn_cipher_name[ | |
372 | ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; | |
373 | fn_cipher_name_set = 1; | |
374 | break; | |
375 | case ecryptfs_opt_fn_cipher_key_bytes: | |
376 | fn_cipher_key_bytes_src = args[0].from; | |
377 | fn_cipher_key_bytes = | |
378 | (int)simple_strtol(fn_cipher_key_bytes_src, | |
379 | &fn_cipher_key_bytes_src, 0); | |
380 | mount_crypt_stat->global_default_fn_cipher_key_bytes = | |
381 | fn_cipher_key_bytes; | |
382 | fn_cipher_key_bytes_set = 1; | |
383 | break; | |
384 | case ecryptfs_opt_unlink_sigs: | |
385 | mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; | |
386 | break; | |
387 | case ecryptfs_opt_mount_auth_tok_only: | |
388 | mount_crypt_stat->flags |= | |
389 | ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; | |
390 | break; | |
391 | case ecryptfs_opt_check_dev_ruid: | |
392 | *check_ruid = 1; | |
393 | break; | |
394 | case ecryptfs_opt_err: | |
395 | default: | |
396 | printk(KERN_WARNING | |
397 | "%s: eCryptfs: unrecognized option [%s]\n", | |
398 | __func__, p); | |
399 | } | |
400 | } | |
401 | if (!sig_set) { | |
402 | rc = -EINVAL; | |
403 | ecryptfs_printk(KERN_ERR, "You must supply at least one valid " | |
404 | "auth tok signature as a mount " | |
405 | "parameter; see the eCryptfs README\n"); | |
406 | goto out; | |
407 | } | |
408 | if (!cipher_name_set) { | |
409 | int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); | |
410 | ||
411 | BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
412 | strcpy(mount_crypt_stat->global_default_cipher_name, | |
413 | ECRYPTFS_DEFAULT_CIPHER); | |
414 | } | |
415 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) | |
416 | && !fn_cipher_name_set) | |
417 | strcpy(mount_crypt_stat->global_default_fn_cipher_name, | |
418 | mount_crypt_stat->global_default_cipher_name); | |
419 | if (!cipher_key_bytes_set) | |
420 | mount_crypt_stat->global_default_cipher_key_size = 0; | |
421 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) | |
422 | && !fn_cipher_key_bytes_set) | |
423 | mount_crypt_stat->global_default_fn_cipher_key_bytes = | |
424 | mount_crypt_stat->global_default_cipher_key_size; | |
425 | ||
426 | cipher_code = ecryptfs_code_for_cipher_string( | |
427 | mount_crypt_stat->global_default_cipher_name, | |
428 | mount_crypt_stat->global_default_cipher_key_size); | |
429 | if (!cipher_code) { | |
430 | ecryptfs_printk(KERN_ERR, | |
431 | "eCryptfs doesn't support cipher: %s", | |
432 | mount_crypt_stat->global_default_cipher_name); | |
433 | rc = -EINVAL; | |
434 | goto out; | |
435 | } | |
436 | ||
437 | mutex_lock(&key_tfm_list_mutex); | |
438 | if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, | |
439 | NULL)) { | |
440 | rc = ecryptfs_add_new_key_tfm( | |
441 | NULL, mount_crypt_stat->global_default_cipher_name, | |
442 | mount_crypt_stat->global_default_cipher_key_size); | |
443 | if (rc) { | |
444 | printk(KERN_ERR "Error attempting to initialize " | |
445 | "cipher with name = [%s] and key size = [%td]; " | |
446 | "rc = [%d]\n", | |
447 | mount_crypt_stat->global_default_cipher_name, | |
448 | mount_crypt_stat->global_default_cipher_key_size, | |
449 | rc); | |
450 | rc = -EINVAL; | |
451 | mutex_unlock(&key_tfm_list_mutex); | |
452 | goto out; | |
453 | } | |
454 | } | |
455 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) | |
456 | && !ecryptfs_tfm_exists( | |
457 | mount_crypt_stat->global_default_fn_cipher_name, NULL)) { | |
458 | rc = ecryptfs_add_new_key_tfm( | |
459 | NULL, mount_crypt_stat->global_default_fn_cipher_name, | |
460 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
461 | if (rc) { | |
462 | printk(KERN_ERR "Error attempting to initialize " | |
463 | "cipher with name = [%s] and key size = [%td]; " | |
464 | "rc = [%d]\n", | |
465 | mount_crypt_stat->global_default_fn_cipher_name, | |
466 | mount_crypt_stat->global_default_fn_cipher_key_bytes, | |
467 | rc); | |
468 | rc = -EINVAL; | |
469 | mutex_unlock(&key_tfm_list_mutex); | |
470 | goto out; | |
471 | } | |
472 | } | |
473 | mutex_unlock(&key_tfm_list_mutex); | |
474 | rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); | |
475 | if (rc) | |
476 | printk(KERN_WARNING "One or more global auth toks could not " | |
477 | "properly register; rc = [%d]\n", rc); | |
478 | out: | |
479 | return rc; | |
480 | } | |
481 | ||
482 | struct kmem_cache *ecryptfs_sb_info_cache; | |
483 | static struct file_system_type ecryptfs_fs_type; | |
484 | ||
485 | /** | |
486 | * ecryptfs_get_sb | |
487 | * @fs_type | |
488 | * @flags | |
489 | * @dev_name: The path to mount over | |
490 | * @raw_data: The options passed into the kernel | |
491 | */ | |
492 | static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, | |
493 | const char *dev_name, void *raw_data) | |
494 | { | |
495 | struct super_block *s; | |
496 | struct ecryptfs_sb_info *sbi; | |
497 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; | |
498 | struct ecryptfs_dentry_info *root_info; | |
499 | const char *err = "Getting sb failed"; | |
500 | struct inode *inode; | |
501 | struct path path; | |
502 | uid_t check_ruid; | |
503 | int rc; | |
504 | ||
505 | sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); | |
506 | if (!sbi) { | |
507 | rc = -ENOMEM; | |
508 | goto out; | |
509 | } | |
510 | ||
511 | rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid); | |
512 | if (rc) { | |
513 | err = "Error parsing options"; | |
514 | goto out; | |
515 | } | |
516 | mount_crypt_stat = &sbi->mount_crypt_stat; | |
517 | ||
518 | s = sget(fs_type, NULL, set_anon_super, flags, NULL); | |
519 | if (IS_ERR(s)) { | |
520 | rc = PTR_ERR(s); | |
521 | goto out; | |
522 | } | |
523 | ||
524 | rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); | |
525 | if (rc) | |
526 | goto out1; | |
527 | ||
528 | ecryptfs_set_superblock_private(s, sbi); | |
529 | s->s_bdi = &sbi->bdi; | |
530 | ||
531 | /* ->kill_sb() will take care of sbi after that point */ | |
532 | sbi = NULL; | |
533 | s->s_op = &ecryptfs_sops; | |
534 | s->s_d_op = &ecryptfs_dops; | |
535 | ||
536 | err = "Reading sb failed"; | |
537 | rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); | |
538 | if (rc) { | |
539 | ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); | |
540 | goto out1; | |
541 | } | |
542 | if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { | |
543 | rc = -EINVAL; | |
544 | printk(KERN_ERR "Mount on filesystem of type " | |
545 | "eCryptfs explicitly disallowed due to " | |
546 | "known incompatibilities\n"); | |
547 | goto out_free; | |
548 | } | |
549 | ||
550 | if (check_ruid && !uid_eq(path.dentry->d_inode->i_uid, current_uid())) { | |
551 | rc = -EPERM; | |
552 | printk(KERN_ERR "Mount of device (uid: %d) not owned by " | |
553 | "requested user (uid: %d)\n", | |
554 | i_uid_read(path.dentry->d_inode), | |
555 | from_kuid(&init_user_ns, current_uid())); | |
556 | goto out_free; | |
557 | } | |
558 | ||
559 | ecryptfs_set_superblock_lower(s, path.dentry->d_sb); | |
560 | ||
561 | /** | |
562 | * Set the POSIX ACL flag based on whether they're enabled in the lower | |
563 | * mount. | |
564 | */ | |
565 | s->s_flags = flags & ~MS_POSIXACL; | |
566 | s->s_flags |= path.dentry->d_sb->s_flags & MS_POSIXACL; | |
567 | ||
568 | /** | |
569 | * Force a read-only eCryptfs mount when: | |
570 | * 1) The lower mount is ro | |
571 | * 2) The ecryptfs_encrypted_view mount option is specified | |
572 | */ | |
573 | if (path.dentry->d_sb->s_flags & MS_RDONLY || | |
574 | mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
575 | s->s_flags |= MS_RDONLY; | |
576 | ||
577 | s->s_maxbytes = path.dentry->d_sb->s_maxbytes; | |
578 | s->s_blocksize = path.dentry->d_sb->s_blocksize; | |
579 | s->s_magic = ECRYPTFS_SUPER_MAGIC; | |
c6751caa MS |
580 | s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; |
581 | ||
582 | rc = -EINVAL; | |
583 | if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { | |
584 | pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); | |
585 | goto out_free; | |
586 | } | |
bdd1545b | 587 | |
588 | inode = ecryptfs_get_inode(path.dentry->d_inode, s); | |
589 | rc = PTR_ERR(inode); | |
590 | if (IS_ERR(inode)) | |
591 | goto out_free; | |
592 | ||
593 | s->s_root = d_make_root(inode); | |
594 | if (!s->s_root) { | |
595 | rc = -ENOMEM; | |
596 | goto out_free; | |
597 | } | |
598 | ||
599 | rc = -ENOMEM; | |
600 | root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); | |
601 | if (!root_info) | |
602 | goto out_free; | |
603 | ||
604 | /* ->kill_sb() will take care of root_info */ | |
605 | ecryptfs_set_dentry_private(s->s_root, root_info); | |
606 | ecryptfs_set_dentry_lower(s->s_root, path.dentry); | |
607 | ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt); | |
608 | ||
609 | s->s_flags |= MS_ACTIVE; | |
610 | return dget(s->s_root); | |
611 | ||
612 | out_free: | |
613 | path_put(&path); | |
614 | out1: | |
615 | deactivate_locked_super(s); | |
616 | out: | |
617 | if (sbi) { | |
618 | ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); | |
619 | kmem_cache_free(ecryptfs_sb_info_cache, sbi); | |
620 | } | |
621 | printk(KERN_ERR "%s; rc = [%d]\n", err, rc); | |
622 | return ERR_PTR(rc); | |
623 | } | |
624 | ||
625 | /** | |
626 | * ecryptfs_kill_block_super | |
627 | * @sb: The ecryptfs super block | |
628 | * | |
629 | * Used to bring the superblock down and free the private data. | |
630 | */ | |
631 | static void ecryptfs_kill_block_super(struct super_block *sb) | |
632 | { | |
633 | struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); | |
634 | kill_anon_super(sb); | |
635 | if (!sb_info) | |
636 | return; | |
637 | ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); | |
638 | bdi_destroy(&sb_info->bdi); | |
639 | kmem_cache_free(ecryptfs_sb_info_cache, sb_info); | |
640 | } | |
641 | ||
642 | static struct file_system_type ecryptfs_fs_type = { | |
643 | .owner = THIS_MODULE, | |
644 | .name = "ecryptfs", | |
645 | .mount = ecryptfs_mount, | |
646 | .kill_sb = ecryptfs_kill_block_super, | |
647 | .fs_flags = 0 | |
648 | }; | |
649 | MODULE_ALIAS_FS("ecryptfs"); | |
650 | ||
651 | /** | |
652 | * inode_info_init_once | |
653 | * | |
654 | * Initializes the ecryptfs_inode_info_cache when it is created | |
655 | */ | |
656 | static void | |
657 | inode_info_init_once(void *vptr) | |
658 | { | |
659 | struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; | |
660 | ||
661 | inode_init_once(&ei->vfs_inode); | |
662 | } | |
663 | ||
664 | static struct ecryptfs_cache_info { | |
665 | struct kmem_cache **cache; | |
666 | const char *name; | |
667 | size_t size; | |
668 | void (*ctor)(void *obj); | |
669 | } ecryptfs_cache_infos[] = { | |
670 | { | |
671 | .cache = &ecryptfs_auth_tok_list_item_cache, | |
672 | .name = "ecryptfs_auth_tok_list_item", | |
673 | .size = sizeof(struct ecryptfs_auth_tok_list_item), | |
674 | }, | |
675 | { | |
676 | .cache = &ecryptfs_file_info_cache, | |
677 | .name = "ecryptfs_file_cache", | |
678 | .size = sizeof(struct ecryptfs_file_info), | |
679 | }, | |
680 | { | |
681 | .cache = &ecryptfs_dentry_info_cache, | |
682 | .name = "ecryptfs_dentry_info_cache", | |
683 | .size = sizeof(struct ecryptfs_dentry_info), | |
684 | }, | |
685 | { | |
686 | .cache = &ecryptfs_inode_info_cache, | |
687 | .name = "ecryptfs_inode_cache", | |
688 | .size = sizeof(struct ecryptfs_inode_info), | |
689 | .ctor = inode_info_init_once, | |
690 | }, | |
691 | { | |
692 | .cache = &ecryptfs_sb_info_cache, | |
693 | .name = "ecryptfs_sb_cache", | |
694 | .size = sizeof(struct ecryptfs_sb_info), | |
695 | }, | |
696 | { | |
697 | .cache = &ecryptfs_header_cache, | |
698 | .name = "ecryptfs_headers", | |
699 | .size = PAGE_CACHE_SIZE, | |
700 | }, | |
701 | { | |
702 | .cache = &ecryptfs_xattr_cache, | |
703 | .name = "ecryptfs_xattr_cache", | |
704 | .size = PAGE_CACHE_SIZE, | |
705 | }, | |
706 | { | |
707 | .cache = &ecryptfs_key_record_cache, | |
708 | .name = "ecryptfs_key_record_cache", | |
709 | .size = sizeof(struct ecryptfs_key_record), | |
710 | }, | |
711 | { | |
712 | .cache = &ecryptfs_key_sig_cache, | |
713 | .name = "ecryptfs_key_sig_cache", | |
714 | .size = sizeof(struct ecryptfs_key_sig), | |
715 | }, | |
716 | { | |
717 | .cache = &ecryptfs_global_auth_tok_cache, | |
718 | .name = "ecryptfs_global_auth_tok_cache", | |
719 | .size = sizeof(struct ecryptfs_global_auth_tok), | |
720 | }, | |
721 | { | |
722 | .cache = &ecryptfs_key_tfm_cache, | |
723 | .name = "ecryptfs_key_tfm_cache", | |
724 | .size = sizeof(struct ecryptfs_key_tfm), | |
725 | }, | |
726 | }; | |
727 | ||
728 | static void ecryptfs_free_kmem_caches(void) | |
729 | { | |
730 | int i; | |
731 | ||
732 | /* | |
733 | * Make sure all delayed rcu free inodes are flushed before we | |
734 | * destroy cache. | |
735 | */ | |
736 | rcu_barrier(); | |
737 | ||
738 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { | |
739 | struct ecryptfs_cache_info *info; | |
740 | ||
741 | info = &ecryptfs_cache_infos[i]; | |
742 | if (*(info->cache)) | |
743 | kmem_cache_destroy(*(info->cache)); | |
744 | } | |
745 | } | |
746 | ||
747 | /** | |
748 | * ecryptfs_init_kmem_caches | |
749 | * | |
750 | * Returns zero on success; non-zero otherwise | |
751 | */ | |
752 | static int ecryptfs_init_kmem_caches(void) | |
753 | { | |
754 | int i; | |
755 | ||
756 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { | |
757 | struct ecryptfs_cache_info *info; | |
758 | ||
759 | info = &ecryptfs_cache_infos[i]; | |
760 | *(info->cache) = kmem_cache_create(info->name, info->size, | |
761 | 0, SLAB_HWCACHE_ALIGN, info->ctor); | |
762 | if (!*(info->cache)) { | |
763 | ecryptfs_free_kmem_caches(); | |
764 | ecryptfs_printk(KERN_WARNING, "%s: " | |
765 | "kmem_cache_create failed\n", | |
766 | info->name); | |
767 | return -ENOMEM; | |
768 | } | |
769 | } | |
770 | return 0; | |
771 | } | |
772 | ||
773 | static struct kobject *ecryptfs_kobj; | |
774 | ||
775 | static ssize_t version_show(struct kobject *kobj, | |
776 | struct kobj_attribute *attr, char *buff) | |
777 | { | |
778 | return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); | |
779 | } | |
780 | ||
781 | static struct kobj_attribute version_attr = __ATTR_RO(version); | |
782 | ||
783 | static struct attribute *attributes[] = { | |
784 | &version_attr.attr, | |
785 | NULL, | |
786 | }; | |
787 | ||
788 | static struct attribute_group attr_group = { | |
789 | .attrs = attributes, | |
790 | }; | |
791 | ||
792 | static int do_sysfs_registration(void) | |
793 | { | |
794 | int rc; | |
795 | ||
796 | ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); | |
797 | if (!ecryptfs_kobj) { | |
798 | printk(KERN_ERR "Unable to create ecryptfs kset\n"); | |
799 | rc = -ENOMEM; | |
800 | goto out; | |
801 | } | |
802 | rc = sysfs_create_group(ecryptfs_kobj, &attr_group); | |
803 | if (rc) { | |
804 | printk(KERN_ERR | |
805 | "Unable to create ecryptfs version attributes\n"); | |
806 | kobject_put(ecryptfs_kobj); | |
807 | } | |
808 | out: | |
809 | return rc; | |
810 | } | |
811 | ||
812 | static void do_sysfs_unregistration(void) | |
813 | { | |
814 | sysfs_remove_group(ecryptfs_kobj, &attr_group); | |
815 | kobject_put(ecryptfs_kobj); | |
816 | } | |
817 | ||
818 | static int __init ecryptfs_init(void) | |
819 | { | |
820 | int rc; | |
821 | ||
822 | if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { | |
823 | rc = -EINVAL; | |
824 | ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " | |
825 | "larger than the host's page size, and so " | |
826 | "eCryptfs cannot run on this system. The " | |
827 | "default eCryptfs extent size is [%u] bytes; " | |
828 | "the page size is [%lu] bytes.\n", | |
829 | ECRYPTFS_DEFAULT_EXTENT_SIZE, | |
830 | (unsigned long)PAGE_CACHE_SIZE); | |
831 | goto out; | |
832 | } | |
833 | rc = ecryptfs_init_kmem_caches(); | |
834 | if (rc) { | |
835 | printk(KERN_ERR | |
836 | "Failed to allocate one or more kmem_cache objects\n"); | |
837 | goto out; | |
838 | } | |
839 | rc = do_sysfs_registration(); | |
840 | if (rc) { | |
841 | printk(KERN_ERR "sysfs registration failed\n"); | |
842 | goto out_free_kmem_caches; | |
843 | } | |
844 | rc = ecryptfs_init_kthread(); | |
845 | if (rc) { | |
846 | printk(KERN_ERR "%s: kthread initialization failed; " | |
847 | "rc = [%d]\n", __func__, rc); | |
848 | goto out_do_sysfs_unregistration; | |
849 | } | |
850 | rc = ecryptfs_init_messaging(); | |
851 | if (rc) { | |
852 | printk(KERN_ERR "Failure occurred while attempting to " | |
853 | "initialize the communications channel to " | |
854 | "ecryptfsd\n"); | |
855 | goto out_destroy_kthread; | |
856 | } | |
857 | rc = ecryptfs_init_crypto(); | |
858 | if (rc) { | |
859 | printk(KERN_ERR "Failure whilst attempting to init crypto; " | |
860 | "rc = [%d]\n", rc); | |
861 | goto out_release_messaging; | |
862 | } | |
863 | rc = register_filesystem(&ecryptfs_fs_type); | |
864 | if (rc) { | |
865 | printk(KERN_ERR "Failed to register filesystem\n"); | |
866 | goto out_destroy_crypto; | |
867 | } | |
868 | if (ecryptfs_verbosity > 0) | |
869 | printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " | |
870 | "will be written to the syslog!\n", ecryptfs_verbosity); | |
871 | ||
872 | goto out; | |
873 | out_destroy_crypto: | |
874 | ecryptfs_destroy_crypto(); | |
875 | out_release_messaging: | |
876 | ecryptfs_release_messaging(); | |
877 | out_destroy_kthread: | |
878 | ecryptfs_destroy_kthread(); | |
879 | out_do_sysfs_unregistration: | |
880 | do_sysfs_unregistration(); | |
881 | out_free_kmem_caches: | |
882 | ecryptfs_free_kmem_caches(); | |
883 | out: | |
884 | return rc; | |
885 | } | |
886 | ||
887 | static void __exit ecryptfs_exit(void) | |
888 | { | |
889 | int rc; | |
890 | ||
891 | rc = ecryptfs_destroy_crypto(); | |
892 | if (rc) | |
893 | printk(KERN_ERR "Failure whilst attempting to destroy crypto; " | |
894 | "rc = [%d]\n", rc); | |
895 | ecryptfs_release_messaging(); | |
896 | ecryptfs_destroy_kthread(); | |
897 | do_sysfs_unregistration(); | |
898 | unregister_filesystem(&ecryptfs_fs_type); | |
899 | ecryptfs_free_kmem_caches(); | |
900 | } | |
901 | ||
902 | MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); | |
903 | MODULE_DESCRIPTION("eCryptfs"); | |
904 | ||
905 | MODULE_LICENSE("GPL"); | |
906 | ||
907 | module_init(ecryptfs_init) | |
908 | module_exit(ecryptfs_exit) |